procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [mq]
> git = keep
> [diff]
> nodates = 1
> EOF
init:
$ hg init repo
$ cd repo
$ echo a > a
$ hg ci -Am adda
adding a
$ echo a >> a
$ hg qnew -f p1
$ echo b >> a
$ hg qnew -f p2
$ echo c >> a
$ hg qnew -f p3
Fold in the middle of the queue:
(this tests also that editor is not invoked if '--edit' is not
specified)
$ hg qpop p1
popping p3
popping p2
now at: p1
$ hg qdiff
diff -r 07f494440405 a
--- a/a
+++ b/a
@@ -1,1 +1,2 @@
a
+a
$ HGEDITOR=cat hg qfold p2
$ grep git .hg/patches/p1 && echo 'git patch found!'
[1]
$ hg qser
p1
p3
$ hg qdiff
diff -r 07f494440405 a
--- a/a
+++ b/a
@@ -1,1 +1,3 @@
a
+a
+b
Fold with local changes:
$ echo d >> a
$ hg qfold p3
abort: local changes found, qrefresh first
[255]
$ hg diff -c .
diff -r 07f494440405 -r ???????????? a (glob)
--- a/a
+++ b/a
@@ -1,1 +1,3 @@
a
+a
+b
$ hg revert -a --no-backup
reverting a
Fold git patch into a regular patch, expect git patch:
$ echo a >> a
$ hg qnew -f regular
$ hg cp a aa
$ hg qnew --git -f git
$ hg qpop
popping git
now at: regular
$ hg qfold git
$ cat .hg/patches/regular
# HG changeset patch
# Parent ???????????????????????????????????????? (glob)
diff --git a/a b/a
--- a/a
+++ b/a
@@ -1,3 +1,4 @@
a
a
b
+a
diff --git a/a b/aa
copy from a
copy to aa
--- a/a
+++ b/aa
@@ -1,3 +1,4 @@
a
a
b
+a
$ hg qpop
popping regular
now at: p1
$ hg qdel regular
Fold regular patch into a git patch, expect git patch:
$ hg cp a aa
$ hg qnew --git -f git
$ echo b >> aa
$ hg qnew -f regular
$ hg qpop
popping regular
now at: git
$ hg qfold regular
$ cat .hg/patches/git
# HG changeset patch
# Parent ???????????????????????????????????????? (glob)
diff --git a/a b/aa
copy from a
copy to aa
--- a/a
+++ b/aa
@@ -1,3 +1,4 @@
a
a
b
+b
Test saving last-message.txt:
$ hg qrefresh -m "original message"
$ cat > $TESTTMP/commitfailure.py <<EOF
> from mercurial import error
> def reposetup(ui, repo):
> class commitfailure(repo.__class__):
> def commit(self, *args, **kwargs):
> raise error.Abort(b'emulating unexpected abort')
> repo.__class__ = commitfailure
> EOF
$ cat >> .hg/hgrc <<EOF
> [extensions]
> # this failure occurs before editor invocation
> commitfailure = $TESTTMP/commitfailure.py
> EOF
$ cat > $TESTTMP/editor.sh << EOF
> echo "==== before editing"
> cat \$1
> echo "===="
> (echo; echo "test saving last-message.txt") >> \$1
> EOF
$ hg qapplied
p1
git
$ hg tip --template "{files}\n"
aa
(test that editor is not invoked before transaction starting,
and that combination of '--edit' and '--message' doesn't abort execution)
$ rm -f .hg/last-message.txt
$ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e -m MESSAGE p3
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: emulating unexpected abort
[255]
$ test -f .hg/last-message.txt
[1]
(reset applied patches and directory status)
$ cat >> .hg/hgrc <<EOF
> [extensions]
> # this failure occurs after editor invocation
> commitfailure = !
> EOF
$ hg qapplied
p1
$ hg status -A aa
? aa
$ rm aa
$ hg status -m
M a
$ hg revert --no-backup -q a
$ hg qpush -q git
now at: git
(test that editor is invoked and commit message is saved into
"last-message.txt")
$ cat >> .hg/hgrc <<EOF
> [hooks]
> # this failure occurs after editor invocation
> pretxncommit.unexpectedabort = false
> EOF
$ rm -f .hg/last-message.txt
$ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e p3
==== before editing
original message
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to use default message.
HG: --
HG: user: test
HG: branch 'default'
HG: added aa
HG: changed a
====
note: commit message saved in .hg/last-message.txt
note: use 'hg commit --logfile .hg/last-message.txt --edit' to reuse it
transaction abort!
rollback completed
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: pretxncommit.unexpectedabort hook exited with status 1
[40]
$ cat .hg/last-message.txt
original message
test saving last-message.txt
(confirm whether files listed up in the commit message editing are correct)
$ cat >> .hg/hgrc <<EOF
> [hooks]
> pretxncommit.unexpectedabort =
> EOF
$ hg status -u | while read f; do rm ${f}; done
$ hg revert --no-backup -q --all
$ hg qpush -q git
now at: git
$ hg qpush -q --move p3
now at: p3
$ hg status --rev "git^1" --rev . -arm
M a
A aa
$ cd ..